This looks like an error in the nwos_get_object_size function. It is calculating the size as 77 when the actual size is 74. The "if (prev_size == 1 && (size == 4 || feature_obj.count == 0 || i+1 == class_def_obj_ptr->count))" statement is triggering and it is adding 3 on the last pass through the loop.